16. a1a2  16... b4a2  17. c1d2  17... f8d8  18. e2e3 In return for the exchange, White has the bishop pair, a great knight on d4, pressure on the queenside, and the black knight is trapped on a2. The computer gives its traditional equality assessment, but in practice the position is difficult to play for Black. Some positions are \"more equal\" than others.